TROJ_OFICLA.SMI
Trojan:Win32/Oficla.AI (Microsoft)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats. As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Arrival Details
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This Trojan drops the following copies of itself into the affected system:
- %User Profile%\Application Data\bmgonsc3tkjk3qwlvtnksgvdhizuhja\csrss.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
It creates the following folders:
- %User Profile%\Application Data\bmgonsc3tkjk3qwlvtnksgvdhizuhja
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Autostart Technique
This Trojan modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "explorer.exe "%User Profile%\Application Data\bmgonsc3tkjk3qwlvtnksgvdhizuhja\csrss.exe""
(Note: The default value data of the said registry entry is Explorer.exe.)
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft
setiasworld = "{random characters}"
It creates the following registry entry(ies) to bypass Windows Firewall:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and file name} = "{malware path and file name}:*:Enabled:ldrsoft"
Download Routine
This Trojan connects to the following malicious URLs:
- http://{BLOCKED}us.ru/cnn/img.php?v=1&id=kudarmdyrphrrefqxydvnmqlrrri2zc&b=&tm=1&os=&av=&br=&
As of this writing, the said sites are inaccessible.
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Identify and terminate files detected as TROJ_OFICLA.SMI
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 3
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Shell = "explorer.exe
To: Shell = "Explorer.exe"
Step 4
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft
- setiasworld = "{random characters}"
- setiasworld = "{random characters}"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- {malware path and file name} = "{malware path and file name}:*:Enabled:ldrsoft"
- {malware path and file name} = "{malware path and file name}:*:Enabled:ldrsoft"
Step 5
Search and delete this folder
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_OFICLA.SMI. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
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